Coolant supply device and grinding tool having a coolant supply device for a machine tool

ABSTRACT

A grinding tool with a coolant supply device for a machine tool and such a coolant supply device. The coolant supply device for the grinding tool has a main body with engagement portions or holes and a line unit for redirecting coolant to a predeterminable processing area of the grinding tool. Using a clamping device, it is possible to releasably secure the coolant supply device to the shaft of the grinding tool. As a result of the attachment of the coolant supply device on the grinding tool, it is possible to tap the coolant of the machine tool via an additional valve device on the connector ring of the machine tool from the standard cooling circuit and supply it to the grinding location in a predeterminable processing area of the grinding tool.

The present invention relates to an exchangeable coolant supply device and a grinding tool having such a coolant supply device for a machine tool with a tool-carrying work spindle, in particular a milling machine.

BACKGROUND

When workpieces are ground, it is necessary to provide the grinding location with sufficient coolant. Grinding machines (i.e. machine tools set up in particular for grinding) are equipped with complex pipe constructions, through which the coolant can be supplied to the desired location. Using methods known to date, this is conducted on special machines, so called grinding machines.

Attempts have recently been made to conduct grinding operations on universal machine tools, milling machines/lathes, machining centers and/or milling machines, where apart from conventional milling/drilling tools, grinding tools can also be introduced and accommodated at tool-carrying work spindles of the universal machine tools, milling machines/lathes, machining centers and/or milling machines.

However, when grinding with grinding tools on universal machine tools, milling machines/lathes, machining centers and/or milling machines, it is usually not possible to direct the standard coolant supply to a grinding location since it has to be unchangedly available e.g. to conventional milling operations.

To the present, there are no satisfactory solutions to supply cooling lubricant to grinding tools when a machine tool, such as a universal machine tool, a milling machine/lathe, a processing center and/or a milling machine, is used.

An object of the present invention is to provide a coolant supply device and a grinding tool with a coolant supply device for a machine tool (in particular with a tool-carrying work spindle), which has a simple design and renders possible improved cooling. In particular, the supply of the coolant from the coolant system of the machine tool to the processing area of the grinding tool shall be improved.

A further object of the invention is to provide a coolant supply device and a grinding tool having a coolant supply device for a machine tool (in particular with tool-carrying work spindle) by means of which it is possible in a flexible and accurate way to use the grinding tool e.g. on universal machine tools, milling machines/lathes, machining centers and/or milling machines with tool-carrying work spindle, wherein, on the one hand, simple, efficient and reliable inserting/exchanging operations can be carried out on the work spindle, in particular by means of automatic tool change apparatuses on the machine tool, and, on the other hand, a reliable, well positionable and easily manageable coolant supply is rendered possible.

SUMMARY OF THE INVENTION

In order to achieve the above mentioned objects, the subjects of the independent claims are proposed. The dependent claims relate to advantageous embodiments of the invention.

The coolant supply device for a grinding tool of a machine tool, in particular with a tool-carrying work spindle, such as a universal machine tool, a milling machine/lathe, of a machining center and/or a milling machine, is equipped with a main body which can comprise at least one engagement hole and/or at least one engagement portion.

In addition, a line unit which is connected to the main body can be provided with a coolant inlet and at least one discharge opening for discharging coolant to a predeterminable processing region. The coolant supply device can have a clamping means for releasably securing the coolant supply device to a shaft of the grinding tool, wherein the coolant supply device can be secured to the machine tool via the engagement hole and/or the engagement portion.

It is thus possible to easily provide a coolant supply for a grinding tool of a universal machine tool, as a result of which the cooling lubricant can be conveyed efficiently and in cost-effective manner to the grinding location in the grinding region.

In particular, a coolant supply device for a grinding tool for use on a machine tool with tool-carrying work spindle is proposed, which has a main body that comprises at least one engagement portion, a line unit which is arranged on the main body and has at least one discharge opening for discharging coolant to a predeterminable processing area at the grinding tool, and a clamping device for releasably attaching the coolant supply device to the grinding tool.

In this connection, the coolant supply device is expediently securable to a connector ring of the work spindle of the machine tool via the engagement portion and/or preferably a plurality of engagement portions, in particular if the grinding tool is accommodated on the work spindle of the machine tool.

In preferred embodiments, the line unit has a coolant inlet which can be docked with a docking device arranged on the connector ring of the work spindle of the machine tool for supplying coolant, in particular if the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion.

In preferred embodiments, the clamping device is configured to secure the coolant supply device to the grinding tool before the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion and/or if the coolant supply device is not secured to the connector ring of the work spindle of the machine tool via the engagement portion.

In preferred embodiments, the clamping device is configured to release the coolant supply device from the securement to the grinding tool if the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion.

In preferred embodiments, a gap is adjusted between the coolant supply device, in particular the clamping device, and the grinding tool in a state in which the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion and the line unit for supplying coolant is docked to the connector ring of the work spindle of the machine tool, preferably in particular in such a way that the grinding tool rotationally driven by the work spindle rotates and/or can rotate without contact with the coolant supply device secured in stationary fashion to the connector ring of the work spindle of the machine tool.

The clamping means and/or the clamping device of the coolant supply device can comprise a slide and a push means (docking element), wherein for securing the coolant supply device to the grinding tool the slide can engage at a first position in a first groove of the grinding tool, in particular in a first groove of the tool connection of the grinding tool and for releasing the coolant supply device, the slide can leave the groove at a second position so as to render possible a relative movement of the grinding tool to the coolant supply device.

Due to this mechanism it is advantageously possible to attach the coolant supply device to the grinding tool in a simple and efficient way, wherein the grinding tool can freely rotate by displacing the slide and, when blocked in the groove by the slide, the grinding tool can be released/clamped together with the coolant supply device and/or can be moved to a magazine of the machine tool.

The machine tool is preferably a milling machine, and therefore it is possible to process workpieces not only with milling processing steps but, by inserting the grinding tool, a grinding operation is also possible, wherein the workpiece does not have to be unclamped to be processed in a grinding machine. The entire processing with milling and grinding processing steps can thus be done while a workpiece remains clamped on the milling machine.

The push means (docking element) of the coolant supply device can advantageously be a tappet, and the clamping means (clamping device) can preferably comprise a spring which is in operative connection to the slide and the tappet.

The main body of the coolant supply device can have at least two engagement holes and/or engagement portions, and the engagement holes and/or engagement portions can be designed in such a way that the coolant supply device can be secured, and can in particular be secured in stationary fashion, to the connector ring of the work spindle (e.g. to a milling head) of the machine tool via clamping elements in the engagement holes and/or engagement portions. It is thus easily possible to clamp a combination tool comprising a grinding tool and a coolant supply device together on the milling machine.

The main body of the coolant supply device can advantageously have a central through-hole for receiving the shaft and/or the tool connection of the grinding tool on the coolant supply device.

The coolant supply device can have a coupling means (coupling device) for coupling the coolant supply device to a coolant circuit of the machine tool (in particular preferably a mechanically controllable, electrically controllable, hydraulically controllable and/or pneumatically controllable coupling device). The coupling means (coupling device) thus renders possible the access to the coolant system of the machine tool.

The coupling agent and/or the coupling device is preferably configured to couple by means of the docking device to the connector ring of the work spindle of the machine tool, in particular in such a way that via the coupling of the coupling device the coolant inlet of the line unit can be supplied by means of the docking device with coolant from the coolant circuit of the connector ring of the work spindle.

The coupling means (coupling device) of the coolant supply device can advantageously comprise a docking cylinder which surrounds at least part of the coolant inlet.

A grinding tool for a machine tool, in particular a milling machine and/or a machine tool with tool-carrying work spindle, can have a shaft, a grinding body provided on the shaft and a coolant supply device arranged on the shaft. This combination tool renders possible to provide a grinding tool with a cooling apparatus, wherein a common insertion from a tool magazine of the machine tool is possible.

The shaft preferably has a workpiece connection to receive the grinding tool on the work spindle of the machine tool, wherein in particular the coolant supply device can preferably be secured to the tool connection of the grinding tool. Such a tool connection can be made e.g. as a hollow shank taper, steep taper or Morse taper.

The coolant supply device of the grinding tool can advantageously be mounted on the grinding tool in floating fashion.

For the floating mounting of the grinding tool of the coolant supply device, a contour part can be provided on the coolant supply device. In order to mount the grinding tool, this contour part can engage in a guide groove of the shaft of the grinding tool, in particular in a groove of the tool connection, and, for mounting in a radial direction, the slide can engage in the first groove.

As a result, it is advantageously possible to mount the coolant supply device in floating fashion if e.g. the grinding tool shall be moved together with the coolant supply device. This is the case if the grinding tool shall be clamped/unclamped together with the coolant supply device or if they shall be moved out of/into the tool magazine.

Before the processing operation begins, it is possible to release the mounting by forming a gap, such that the grinding tool can freely rotate and the coolant supply device remains fixedly or stationarily connected to the connector ring of the tool spindle and/or the spindle housing or milling head of the machine tool without co-rotating.

In a securing position, the clamping means (clamping device) of the grinding tool can secure the coolant supply device to the shaft of the grinding tool in a radial direction and in a release position can allow a rotation of the shaft about a longitudinal axis relative to the coolant supply device. In the securing position, a rotation of the shaft about a longitudinal axis relative to the coolant supply device is thus blocked and is released in the release position.

In order to switch between the release position and the securing position of the grinding tool, the push means (docking element) can be actuated.

The shaft and/or the tool connection of the grinding tool can advantageously have a (first) groove into which the slide of the coolant supply device is guided, wherein the securing position the slide engages in the (first) groove of the grinding tool and in the release position the slide leaves the groove so as to render possible a relative movement of the grinding tool to the coolant supply device.

The discharge opening of the line unit of the grinding tool can be arranged in the grinding body region in such a way that a cooling lubricant can be supplied from the discharge opening to a work area of the grinding body for lubricating and/or cooling purposes, wherein the alignment and/or orientation of the discharge opening of the line unit can be adjusted in particular mechanically, electrically, pneumatically and/or hydraulically and/or the line unit is in particular releasably attached.

The grinding tool can additionally be provided for a milling head of a machine tool.

The push means of the grinding tool can advantageously be movable along a movement axis which is parallel to the longitudinal axis of the shaft.

A machine tool can be equipped with a work spindle which has a tool support and a connector ring which can be arranged in the area of the tool support.

The connector ring can have at least one inner line system for coolant and a clamping means, wherein a switching member can be provided for switching the coolant flow from the inner line system of the connector ring to a contactable coolant supply device. As a result, it is advantageously possible to attach a coolant supply device to the standard coolant circuit of the machine tool so as to render possible a switching depending on the processing operation. When milling on the machine tool, the standard nozzles can be used for the coolant and during grinding it is possible, when connecting the coolant supply device, to switch to them in order to be able to supply the coolant directly to the grinding location.

In particular, a machine tool is proposed, in particular a machine tool having a tool-carrying work spindle which has a tool support and a connector ring, which is arranged in the area of the tool support, wherein the connector ring has at least one inner line system for coolant and a clamping device for clamping at least one engagement portion of a coolant supply device according to at least one of the above aspects and wherein a switching member can preferably be provided on the connector ring in order to switch the coolant flow from the inner line system of the connector ring to a docking device (of the connector ring) for coupling to the coolant supply device.

The machine tool can comprise a tool changer and a tool magazine, wherein the tool changer can be configured to exchange a tool which is clamped on the work spindle with a tool from the tool magazine and wherein a grinding tool can be received together with the coolant supply device in the magazine and be inserted by the tool changer. An automated insertion of the grinding tool including the attached coolant supply device is thus advantageously possible.

The combination tool comprising the coolant supply device and the grinding tool can be switched to the release position by the switching member when the combination tool is clamped in the work spindle by contacting the coupling means (coupling device). This serves to automatically switch from the standard coolant circuit to the coolant supply device when the combination tool is clamped/unclamped.

The coolant supply device of the machine tool can be switched with the grinding tool to the securing position when it is arranged in the tool magazine and to the release position when it is arranged on the work spindle.

The machine tool can be a milling machine. Thus, it is advantageously possible to clamp a grinding tool with optimum cooling in the milling machine and at the same time to ensure optimized cooling at the grinding location without having to insert an additional cooling block. A separate grinding machine is therefore not necessary.

In order to dock the coolant supply device to the machine tool, the clamping means (clamping device) of the connector ring can engage in the engagement holes and/or engagement portions of the coolant supply device and the coolant supply device can be pulled axially towards the connector ring, and in addition the grinding tool can be received at the support of the work spindle of the machine tool, wherein, as a result of the docking of the coolant supply device and the receiving of the grinding tool, a gap between the coolant supply device and the grinding tool can preferably be secured or adjusted. A free rotation of the grinding tool is thus possible (e.g. with driven rotation by the rotating work spindle about the spindle axis), irrespective of the provided coolant supply device.

During the docking operation, the tappet (docking element) of the machine tool can advantageously be actuated.

The switching member can advantageously have an inner cylinder and a switching sleeve guided on the inner cylinder, wherein for switching the coolant flow from the inner line system to the coolant supply device the switching sleeve is moved relative to the switching cylinder by a docking cylinder of the coupling means to release switching bores of the inner cylinder and redirect the coolant flow.

Advantageous embodiments and further details of the present invention as well as further aspects and the advantages thereof as well as advantages and more specific design possibilities of the above described aspects and features are described in the following descriptions and explanations regarding the attached drawings, which should, however, by no means be considered limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows, by way of example, a diagram of a conventional grinding tool on a work spindle of a machine tool;

FIG. 2 shows, by way of example, a diagram of a grinding tool with a coolant supply device according to an embodiment;

FIG. 3 shows, by way of example, a diagram of the grinding tool having a coolant supply device according to FIG. 1 on a work spindle of a machine tool according to an embodiment;

FIG. 4 shows, by way of example, a diagram of the work spindle of the machine tool according to FIG. 3 without received grinding tool;

FIG. 5 shows, by way of example, a sectional view of the grinding tool with the coolant supply device according to FIG. 1 on the work spindle of the machine tool according to an embodiment;

FIG. 6 shows, by way of example, a detailed view of the gap between grinding tool and coolant supply device according to FIG. 1 on the work spindle of the machine tool according to an embodiment;

FIG. 7 shows, by way of example, a diagram of a grinding tool with a coolant supply device and a connector ring on a work spindle of a machine tool;

FIG. 8 shows a further exemplary view of the connector ring of the work spindle of the machine tool;

FIG. 9 shows an exemplary sectional view through the connector ring of the machine tool;

FIG. 10a shows, by way of example, an inner cylinder of the switching member of the connector ring of the machine tool;

FIG. 10b shows, by way of example, a switching sleeve of the switching member of the connector ring of the machine tool;

FIG. 11 shows an exemplary sectional view of the switching member;

FIG. 12 shows an exemplary grinding tool with a coolant supply device mounted thereon;

FIG. 13 shows a further exemplary diagram of the grinding tool with the coolant supply device;

FIG. 14 shows an exemplary detailed view of the clamping means of the coolant supply device; and

FIG. 15 shows an exemplary view of the grinding tool with the coolant supply device in a tool magazine.

DETAILED DESCRIPTION OF THE DRAWINGS AND OF EMBODIMENTS

Examples and/or embodiments of the present invention are described in detail below with reference to the enclosed drawings. The same or similar elements in the drawings can here be designated by the same reference signs and sometimes also by different reference signs.

However, it should be noted that the present invention is by no means limited or confined to the below described embodiments and the design features thereof but further comprises modifications of the embodiments, in particular those which are comprised by modifications of the features of the described examples and/or by combination of one or more of the features of the described examples on the basis of the scope of protection of the independent claims.

FIG. 1 shows, as an example, a diagram of a conventional grinding tool 200 on a work spindle 100 of a machine tool. The work spindle 100 comprises a connector ring 110 around a tool support 130, in which a tool connection (e.g. a hollow shank taper, steep taper or Morse taper) of a tool can be clamped, in particular to drive a rotation of the tool.

Conventional coolant nozzles 120 of a coolant supply are arranged on the connector ring 110 and can feed coolant to the tool received on the work spindle during processing. This is usually referred to as AKZ or outer coolant supply (to be distinguished in particular from inner coolant supply, IKZ, which can be docked in the tool supply 130).

As an example, FIG. 1 shows a grinding tool 200 having a grinding wheel 210 on a shaft 220, which is received and/or clamped on the tool support 130 of the work spindle 100 by means of the tool connection 221 (e.g. made as HSK or hollow shank taper).

However, it is shown herein that a direct and accurate coolant supply by means of the nozzles 120 is not possible with adequate accuracy and in targeted fashion to the grinding wheel. This is improved and rendered possible with greater accuracy by means of a coolant supply device of the invention and in particular the following embodiments.

FIG. 2 shows, by way of example, a diagram of a grinding tool A3 with a coolant supply device A2 according to an embodiment. The coolant supply device A2 and the grinding tool A3 form e.g. a combination tool of an embodiment.

Analogous to FIG. 1, the grinding tool A3 has e.g. a grinding wheel A3 b (grinding body) which is arranged on a shaft having a tool connection A3 c with a gripper flute A3 d (groove). The tool connection A3 c is again made e.g. as a hollow shank taper (HSK). However, tool connections can also be made differently, e.g. as steep tapers or Morse tapers.

In addition, the coolant supply device A2 can be attached e.g. to the tool connection. However, it is also possible to attach the coolant supply device A2 on the shaft above the tool connection.

The coolant supply device A2 has e.g. a main body A2 b, which has e.g. two protruding portions with respective engagement portions A2 a (e.g. holes). The coolant supply device A2 also has e.g. a clamping device A2 c for fixation to the tool connection A3 c of the grinding tool A3.

When not clamped to the work spindle, the clamping device A2 c preferably secures the grinding tool A3 to the coolant supply device A2 and/or the coolant supply device A2 to the grinding tool A3.

Furthermore, the coolant supply device A2 has e.g. a line unit A1 with a discharge opening A1 a for discharging coolant to the grinding wheel A3 b, wherein the line unit A1 is e.g. attached to a side of an inlet portion A1 c on the main body and/or a portion of the engagement portions A2 a of the coolant supply device A2.

For example, the line unit A1 is releasably attached (e.g. by means of a screw connection), in particular preferably for replacement with other, shorter, longer and/or differently shaped line units, e.g. for other tool forms (e.g. depending on the shaft length and/or grinding wheel thickness and/or diameter) or for maintenance purposes.

The line unit A1 can also have flexible portions and/or joints which are manually moldable, bendable, slidable, adjustable in length or manually adjustable in any other way, e.g. for manually adjusting the position and/or alignment of the discharge opening A1 a. In further embodiments, the line unit A1 can additionally or alternatively have adjustment devices which render possible an electric, hydraulic, pneumatic or other adjustment of the position and/or alignment of the discharge opening A1 a.

Additionally or alternatively it is possible for a nozzle adjustment of the discharge opening A1 a being manually, electrically, pneumatically and/or hydraulically adjustable. Furthermore, it is possible to provide, additionally or alternatively to the line unit A1 for coolant, also other lines e.g. for sealing air or hydraulic systems.

FIG. 3 shows, as an example, a diagram of the grinding tool A3 with the coolant supply device A2 according to FIG. 1 on a work spindle 100 of a machine tool according to an embodiment.

As an example, the connector ring B of the work spindle 100 has, in addition to the nozzles B3, additional clamping elements B1 and a docking device B2.

When the grinding tool A3 is removed from a tool magazine together with the coolant supply device A2 and is inserted and the tool connection A3 c of the grinding tool A3 is received and clamped in the tool support 130 of the work spindle 100 (wherein the tool connection A3 c is pulled towards the work spindle 100 so as to be clamped), the exemplary openings of the engagement portions A2 a of the coolant supply device A2 engage in the clamping elements B1 of the connector ring B of the work spindle 100 where they are positioned and centered at the predetermined position.

This clamps the coolant supply device A2 by means of the engagement portions A2 a at a predetermined position on the connector ring B of the work spindle 100 in stationary fashion and secures the coolant supply device A2 to the connector ring B of the work spindle 100 when the grinding tool A3 is received and clamped on the tool support 130 of the work spindle 100.

In addition, a coupling device of the coolant supply device A2 (described below) is coupled in this clamping state to a docking element of a docking device B2 that is arranged on the connector ring B of the work spindle 100, preferably to supply coolant from the cooling circuit of the outer coolant supply of the work spindle to the line element A1.

FIG. 4 shows, by way of example, a diagram of the work spindle of the machine tool according to FIG. 3 without accommodated grinding tool. As an example, the connector ring B of the work spindle 100 is expanded by the clamping device with the clamping elements B1 and the docking device B2 in contrast to the conventional design according to FIG. 1.

The docking device B2 is connected to a coolant supply circuit of the connector ring B of the work spindle 100 and/or can preferably be connected by switching a valve.

FIG. 5 shows, by way of example, a sectional view of the grinding tool with the coolant supply device according to FIG. 1 on the work spindle of the machine tool according to an embodiment. It is here shown that the tool connection A3 c is clamped in the tool support 130 and is pulled towards the work spindle.

The openings of the engagement portions A2 a of the coolant supply device A2 are in this case arranged e.g. on opposite sides, and the clamping elements B1 of the clamping device of the connector ring B of the work spindle 100 engage in these, thus centering and positioning the coolant supply device A2 at an accurate predetermined position on the connector ring B of the work spindle 100 when the grinding tool A3 is received and clamped at the tool spindle 100.

However, in order to render possible that in this stationarily clamped state of the coolant supply device A2 the grinding tool A3 can rotationally be driven in an unimpeded and friction-free manner at the work spindle 100, the clamping device A2 c of the coolant supply device A2 is configured in such a way that in the stationarily clamped state of the coolant supply device A2 it releases the clamping of the grinding tool A3 and a gap is adjusted between the grinding tool A3 and the coolant supply device A2, in particular preferably between the tool connection of the grinding tool A3 and the clamping device A2 c of the coolant supply device A2.

FIG. 6 shows, by way of example, a detailed view of the above mentioned gap between grinding tool and coolant supply device according to FIG. 1 on the work spindle of the machine tool according to an embodiment.

FIG. 7 shows, by way of example, a diagram of a grinding tool having a coolant supply device and a connector ring on a work spindle of a machine tool.

FIG. 7 shows the grinding tool A3 (and/or a grinding tool holder for receiving a grinding wheel), on which the coolant supply device A2 (coolant supply device) is arranged.

The grinding tool A3, which is connected e.g. to the coolant supply device A2, is referred to, by way of example, as combination tool A. This combination tool A can be received e.g. in a tool magazine of a machine tool in designated receptacles or tool receptacles and can be automatically introduced and/or exchanged during the insertion via a tool changer of the machine tool (see FIG. 15).

The machine tool, which can be in particular a machine tool having a tool-carrying work spindle (e.g. milling machine, universal machine tool, milling machine/lathe, machining center), and which in addition preferably comprises a tool change apparatus, can automatically remove the combination tool A from the tool magazine and can position, accommodate and clamp it on the work spindle of the machine tool and also exchange it again by means of the tool change apparatus and place it in the tool magazine or a receptacle of the tool magazine.

In the present embodiment, the grinding tool A3 is merely made by way of example with a hollow shank taper as a tool connection for accommodation in the work spindle. However, the present invention is not limited to designs with hollow shank taper as a tool connection but it is also possible to use further tool connections, in particular e.g. steep tapers or Morse tapers in addition to the illustrated hollow shank taper.

Such tool connections usually have portions where the tool connection, e.g. for the tool change on the work spindle and/or for accommodation from the tool magazine can be gripped by a gripper device of the tool change device. In the present embodiment, such a portion (gripper portion) is merely made by way of example as a gripper flute on the hollow shank taper as a tool connection.

In order to connect the combination tool A to the work spindle of the machine tool, the connector ring B is provided which has clamping means (clamping portions and/or clamping elements) B1, to which the engagement portions and/or in particular the engagement holes of the coolant supply device A2 can be docked.

In particular, the clamping means B1 of the connector ring B are made e.g. as a drilling clamping mechanism which, for positioning and clamping the coolant supply device A2, are inserted in the engagement holes of the coolant supply device A2 in order to position and clamp them. The connector ring B of the machine tool also has e.g. the coolant supply elements B3 (nozzles), which are the standard coolant supply nozzles of the machine tool.

The grinding tool A3 is clamped and secured to the work spindle of the machine tool via the tool connection. The shaft of the grinding tool A3 preferably has an HSK (hollow shank taper) support as a tool connection for clamping on the work spindle. As already mentioned, such an HSK (hollow hank taper) has a tool connection body having a gripper flute and a support portion for receiving and clamping on the work spindle.

As an example, the coolant supply device is arranged on or attached to the tool connection body on the shaft of the grinding tool. In this connection, an element engage e.g. in the circumferential gripper flute of the tool connection body and secures the coolant supply device A2 axially to the tool connection body on the shaft of the grinding tool A3.

In addition, e.g. a spring-loaded slide is provided which can engage in a lateral groove on the tool connection body to radially secure the coolant supply device A2.

In order to clamp the coolant supply device A2 via the engagement holes (engagement portions) on the connector ring B, it is positioned, centered and clamped e.g. via the two drilling clamping mechanisms (clamping elements and/or clamping means B1).

When the grinding tool A3 is jointly inserted together with the coolant supply device A2 by the tool changer, the engagement holes of the coolant supply device A2 are threaded into the clamping means B1 (clamping elements and/or drilling clamping mechanisms).

When the tool A3 is now clamped on the work spindle, a predetermined, circumferential gap is adjusted between the grinding tool (and/or the tool connection body) and the docked coolant supply device A2 (see FIG. 6).

As a result of the movement of the tappet (docking element), the slide of the clamping means A2 c is also pressed out of the first groove A3 e. The coolant supply device A2 is thus stationarily secured to the milling head or the connector ring B, and the grinding tool A3 with the grinding body (grinding disk) can freely move on account of the gap.

In order to also keep this gap free during processing and to avoid friction by possibly penetrating dirt, further nozzles can be provided which introduce, inject and/or blow sealing air and/or coolant or lubricant on or in the gap in order to be able to avoid a friction-causing penetration of undesired dust and/or chip dirt into the gap.

The described connecting process between the combination tool A and the connector ring B is also referred to as docking. In this docking, the coolant supply from the standard coolant supply elements B3 is switched to the introduced coolant supply device A2 by a sliding mechanism which is available as a switching member B2 (docking device). As a result, the entire cooling lubricant volume flow can be used for grinding, if required.

When the combination tool A is exchanged, the coolant supply is again automatically switched to the coolant supply element B3 of the inner coolant circuit of the connector ring B of the machine tool.

By providing the combination tool A, which comprises the grinding tool A3 and the coolant supply device A2, and by providing the switching possibility by the switching member B2 on the connector ring B of the machine tool, it is possible to use a grinding tool on a milling machine, wherein the standard coolant supply of the milling machine can be advantageously tapped to convey the cooling lubricant to the grinding location of the grinding tool A3.

Individual coolant supply devices A2 can be provided for different grinding tools A3 with different grinding bodies, said coolant supply devices having an adapted line run so as to always position in optimum fashion the discharge opening for the cooling lubricant for the respective tool.

In further embodiments, the alignment or orientation of the discharge opening can also be adjustable manually, electrically, pneumatically and/or hydraulically.

This combination tool A is markedly cheaper than the insertion of a separate nozzle block for the supply of the cooling lubricant. In addition, as a result of the use of the combination tool A, no additional change unit and no additional coolant supply elements are necessary on the connector ring B of the machine tool to convey the cooling lubricant to the desired grinding location.

FIG. 8 shows a further exemplary view of the connector ring of the work spindle of the machine tool.

FIG. 8 illustrates, by way of example, the connector ring B. This ring is provided on the machine tool in the area of the work spindle. An inner coolant circuit is provided in the connector ring B. The cooling lubricant is transported via this coolant circuit to the respective coolant supply elements B3, which are made in particular as nozzles.

When the machine tool is used for milling, the cooling lubricant is conveyed via these nozzles B3 directly to the processing areas of the milling cutter. If a grinding tool is inserted on the milling machine instead of a milling cutter, this grinding tool typically has an elongated shaft. In particular in the case of grinding tools having a grinding body which is a grinding wheel, such an elongated shaft is necessary to be able to process specific areas of the workpiece.

In order to achieve a sufficient supply of the cooling lubricant for the inserted grinding tool, the standard coolant supply elements B3 are, however, not sufficient. It is e.g. proposed to tap the inner cooling lubricant circuit (e.g. the AKZ) via the cooling lubricant switching member B2 and to redirect the cooling lubricant from the coolant supply elements B3 to convey it specifically to the grinding location via a coolant supply device A2.

In the illustrated embodiment, the cooling lubricant switching member B2 is provided with an inner cylinder B4 and a switching sleeve B5. If a hollow cylinder is pressed on this switching sleeve B5 when the coolant supply device A2 docks to the connector ring B, this switching sleeve B5 moves inwards and releases upper switching holes Bob of the inner cylinder B4, such that the cooling lubricant can be conveyed from the connector ring B into the coolant supply device A2.

The clamping means B1 are provided to attach the coolant supply device A2, said clamping means being in particular e.g. clamping bolts. These clamping bolts or clamping elements B1 engage in the engagement holes (engagement portions) of the coolant supply device A2 and secure them.

The connector ring B additionally has e.g. the support B6, which is e.g. a through hole, through which the end cap of the tool connection A3 c of the grinding tool A3 can be connected to the tool support 130 of the work spindle of the machine tool to apply the torque of the machine tool to the grinding tool.

FIG. 9 shows an exemplary sectional view through the connector ring of the machine tool.

FIG. 9 illustrates an exemplary section through the clamping means B1 (clamping element) and the switching member B2 of the valve device. The switching member B2 comprises e.g. a switching sleeve B5, which is forced out of the connector ring B via a spring B8. The movement of the switching sleeve B5 is limited via an inner cylinder B4, which is screwed into the connector ring B.

The cooling lubricant is supplied to the coolant supply elements B3 via the inner cooling lubricant circuit B9 to ensure an appropriate coolant supply during the milling operation of the machine tool.

During the docking operation of the coolant supply device A2, the switching sleeve B5 is pressed into the connector ring B against the spring force of the spring B8 for the grinding operation of the milling machine in order to release the upper switching hole of the inner cylinder B4 and simultaneously close the lower switching hole B4 a of the inner cylinder Bob.

This closure serves to block a supply of the coolant to the inner cooling lubricant circuit B9. The cooling lubricant can here be supplied via the cooling lubricant circuit B7.

FIG. 10a shows, by way of example, an inner cylinder of the switching member of the connector ring of the machine tool and FIG. 10b shows, by way of example, a switching sleeve of the connector ring of the machine tool.

FIG. 10a and FIG. 10b show in detail the inner cylinder B4 and the switching sleeve B5. The inner cylinder B4 of the switching member B2 has a covering surface B4 c, which has a larger diameter than the remaining cylinder body to thus delimit, as an upper stop for the switching sleeve B5, the axial movement of the switching sleeve from the connector ring B.

The inner cylinder B4 is e.g. hollow and, for a redirection of the cooling lubricant, has an inner space B4 f and lower switching holes B4 a and upper switching holes Bob. In the base area of the inner cylinder B4, e.g. the bottom area B4 e is provided which serves as a connection point to the cooling lubricant circuit of the machine tool, wherein a phase B4 d (e.g. thread recess) is provided in addition in the base area of the inner cylinder B4.

The switching sleeve B5 has an inner sliding surface B5 b, along which the switching sleeve B5 glides along the outer surface of the inner cylinder B4. The inner gliding surface B5 b has, on the front side of the switching sleeve B5, a step which is designed as a counter member of the cover surface B4 c of the inner cylinder B4 in order to confine the axial movement of the switching sleeve B5. The outer gliding surface B5 d of the switching sleeve B5 glides in the connector ring B5. The switching sleeve B5 also has the supply holes B5 c for switching the cooling lubricant flow.

Four symmetric holes are preferably provided as supply holes B5 c. The inner cylinder B4 also has preferably in each case four lower switching holes B4 a and four upper switching holes Bob, which are arranged symmetrically along the circumference in a plane of the inner cylinder B5.

FIG. 11 shows an exemplary sectional view of the switching member. FIG. 11 depicts a sectional view of the inner cylinder B4, which is introduced into the switching sleeve B5. The step of the cover surface B4 c is here in contact with the inner gliding surface B5 d of the switching sleeve B5.

The switching sleeve B5 additionally has the contact surface B5 a where the coupling means of the coolant supply device A2 engages to displace the sleeve during the docking operation to the connector ring B4. As a result, the upper switching hole Bob is released and the lower switching hole B4A is thus blocked.

In this connection, the lower switching hole B4 a is blocked by displacing the sleeve into the base area of the inner cylinder, such that the supply hole B5 c is no longer overlapped with the lower switching hole B4 a. In order to secure the switching member B2, a thread B4 g is provided e.g. on the inner cylinder B5.

FIG. 12 shows an exemplary grinding tool with a coolant supply device mounted thereon. FIG. 12 shows the combination tool A, which is composed of the grinding tool A3 and the attached coolant supply device A2. The coolant supply device A2 comprises a main body A2 b, which has an outlet opening in the center, through which the shaft A3 a of the grinding tool A3 is passed.

In addition, the main body A2 b has radial projections A2 d (radial offset on both sides). The radial projections A2 d are preferably arranged on opposite sides to improve the power transmission to the connector ring B in the docked state.

The radial projections A2 d (radial offset) have engagement holes A2 a, through which the clamping means B1 of the connector ring B can be passed through to secure the main body A2 b.

For the floating support of the coolant supply device A2, the clamping means A2 c is provided at the grinding tool A3. The clamping means A2 c is arranged in a circumferential region of the main body A2 b.

The shaft A3 a of the grinding tool A3 has e.g. the guide groove A3 d, which guides a contour part A2 h for the floating support of the coolant supply device A2.

The clamping means A2 c additionally has a mechanism, via which it is possible to radially secure the grinding tool A3 with respect to the coolant supply device A2. In order to clamp the grinding tool A3 into the spindle of the machine tool or the milling machine, the shaft A3 a of the grinding tool A3 has a grinding tool attachment A3 c. This grinding tool attachment A3 c can introduce the rotary motion of the machine tool into the shaft A3 a via a groove.

However, it should be noted that such a drive groove can be provided in particular in the case of hollow shank taper tool connections. Other tool connections can also have other or different drive portions.

The grinding body A3 b, which is preferably a grinding wheel, is provided on the front side of the shaft A3 a. A processing area A3 c is also provided on the grinding body A3 b and is intended for contacting a workpiece.

The discharge opening A1 a of the coolant supply device A2 is directed to this processing region A3 c. The coolant is conveyed from a docking cylinder A1 d, which can be contacted with the switching member B2 of the connector ring B and via which the cooling lubricant is supplied in the line unit A1, via the line unit A1 and along the longitudinal pipe A1 b to the discharge opening A1 a.

The cooling lubricant is thus conveyed from the cooling lubricant circuit of the milling machine (machine tool) towards the discharge opening A1 a via the docking cylinder A1 d to optimally provide the grinding location cooling lubricant. The longitudinal pipe A1 b of the line unit A1 is secured via the fixation A1 c.

FIG. 13 shows a further exemplary diagram of the grinding tool with the coolant supply device.

FIG. 13 shows the combination tool A. In order to supply the cooling lubricant to the discharge opening A1 a, the cooling lubricant inlet Ale is provided, which is arranged in the cavity of the docking cylinder A1 d. The docking cylinder A1 d has contact surfaces which serve to press the switching sleeve of the switching member B2 into the connector ring B to tap the cooling lubricant from the connector ring B and pass it on to the discharge opening A1 a via the longitudinal pipe A1 b.

The clamping means A2 c has a tappet A2 e (docking element), which is pressed into the clamping means A2 c when contacting the combination tool A with the processing unit of the machine tool so as to release the radial movement of the grinding tool A3 (i.e. the shaft A3 a and the grinding body A3 b), such that the grinding tool A3 can rotate independently of the coolant supply device A2.

The tappet A2 e is pressed into the clamping means A2 c when the combination tool A docks to the connector ring B here via the contacting element B10. The contacting element B10 preferably has a tongue which is made as a rigid lever. This rigid lever presses the tappet A2 e into the clamping means A2 c, such that the radial movement of the grinding tool A3 can be released since the slide A2 g can move out of the axial groove A3 c. This adjusts the above described gap (see FIG. 6).

FIG. 14 shows an exemplary detailed view of the clamping means of the coolant supply device.

FIG. 14 shows a sectional view of the clamping means A2 c. For securing or releasing the shaft A3 a of the grinding tool A3, the tappet A2 e is pressed into the clamping means A2 c against the spring A2 f to thus move the slide A2 g fixedly connected to the tappet A2 e out of a first groove A3 e (axial groove).

When the release position is achieved, the tappet A2 e (docking element) has entered the clamping means A2 c to such an extent that the slide A2 g has fully left the first groove A3 e and a rotation of the shaft A3 a is possible without blocking by the slide A2 g.

The floating support of the coolant supply device A2 on the grinding tool A3 is also achieved via the contour part A2 h. The contour part A2 h has a projection, which is adapted in a second groove A3 d (radial groove) and is spaced apart therefrom at a small distance, preferably 0.5 mm.

The contour part A2 h has an opening in which the spring A2 f is arranged and through which the tappet A2 e is passed to be connected to the slide A2 g via a screw connection.

The side wall A2 j of the main body A2 b is connected to the contour part A2 h. The contour part A2 h is preferably screwed to the side wall A2 j of the main body A2 d and secured via a cover A2 i.

FIG. 15 shows an exemplary view of the grinding tool A3 having the coolant supply device A2 (combination tool A) in a tool magazine 300 of the machine tool.

The tool magazine 300 (shown only as a partial view) is made e.g. as a wheel magazine, with a wheel 320, where a plurality of tool receptacles 309, 310 and 311 are arranged. For example, the grinding tool A3 with coolant supply device A2 is received and held at the tool receptacle 310 by means of the tool connection.

For example, the engagement portions of the coolant supply device A2 are arranged via the adjacent tool receptacles 309 and 311 and can be positioned there also by means of additional centering elements. These tool receptacles 309 and 311 are preferably kept free but other tool receptacles of the tool magazine can be provided conventionally with other tools.

For example, the grinding tool A3 with the coolant supply device A2 is held at the tool magazine in such a way that it is rotated by 180° compared to the clamping situation on the work spindle so as to be inserted at the work spindle with proper orientation in the case of a rotation by 180° by means of a gripper of a tool change apparatus.

Since the gripper flute of the tool connection can always be gripped or be free for being gripped by means of a gripper of a tool change device at both the work spindle and the work spindle, at least on the side opposite the clamping device A2 c, such a combination tool can be inserted and exchanged advantageously in an easy and reliable way and in fully automated fashion with tool change apparatuses known to date.

Examples and/or embodiments of the present invention and the advantages thereof have been described above in detail with reference to the enclosed drawings.

However, it shall be pointed out again that the present invention is by no means limited or confined to the above described embodiments and the design features thereof but comprises further modifications of the embodiments, in particular those which are comprised by modifications of the features of the described examples and/or by combination of one or more of the features of the described examples on the basis of the scope of protection of the independent claims. 

1. A coolant supply device for a grinding tool for use on a machine tool with tool-carrying work spindle, comprising a main body, which includes at least one engagement portion, a line unit, which is arranged on the main body and has at least one discharge opening for discharging coolant to a predeterminable processing region on the grinding tool, and a clamping device for releasably attaching the coolant supply device onto the grinding tool, wherein the coolant supply device can be secured to a connector ring of the work spindle of the machine tool via the engagement portion when the grinding tool is received on the work spindle of the machine tool.
 2. The coolant supply device according to claim 1, wherein the line unit has a coolant inlet which can dock by means of a docking device arranged on the connector ring of the work spindle of the machine tool for supplying coolant when the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion.
 3. The coolant supply device according to claim 1, wherein the clamping device is configured to secure the coolant supply device to the grinding tool before the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion.
 4. The coolant supply device according to claim 3, wherein the clamping device is configured to release the coolant supply device from being secured to the grinding tool when the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion.
 5. The coolant supply device according to claim 4, wherein in the state in which the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion and the line unit for supplying coolant is docked to the connector ring of the work spindle of the machine tool, a gap is adjusted between the coolant supply device and the grinding tool in such a way that the grinding tool rotationally driven by the work spindle is rotated without contact to the coolant supply device stationarily secured to the connector ring of the work spindle of the machine tool.
 6. The coolant supply device according to claim 1, wherein the clamping device comprises a slide and a docking element and wherein, in a first position, the slide engages in a first groove of a tool connection of the grinding tool in such a way that a rotary motion of the grinding tool about the shaft of the grinding tool is blocked and, in order to release the coolant supply device, the slide leaves the first groove in a second position so as to render possible a movement of the grinding tool about the shaft relative to the coolant supply device.
 7. The coolant supply device according to claim 6, wherein the docking element is a tappet and the clamping device comprises a spring, which is in operative connection to the slide and the tappet.
 8. The coolant supply device according to claim 1, wherein the main body has at least two engagement portions and the engagement portions are designed in such a way that the coolant supply device is stationarily securable to the connector ring of the work spindle of the machine tool via clamping elements in the engagement portions.
 9. The coolant supply device according to claim 1, wherein the main body has a central through hole for receiving the grinding tool at the coolant supply device.
 10. The coolant supply device according to claim 1, wherein the coolant supply device has a coupling device for coupling the coolant supply device to a coolant circuit of the machine tool, the coupling device being a mechanically controllable, electrically controllable, hydraulically controllable and/or pneumatically controllable coupling device.
 11. The coolant supply device according to claim 10, wherein the line unit has a coolant inlet, which can dock by means of a docking device arranged on the connector ring of the work spindle of the machine tool for supplying coolant when the coolant supply device is secured to the connector ring of the work spindle of the machine tool via the engagement portion; and the coupling device is configured to couple by means of the docking device to the connector ring of the work spindle of the machine tool, such that via the coupling of the coupling device to the docking device coolant from the coolant circuit of the connector ring of the work spindle can be supplied to the coolant inlet of the line unit.
 12. The coolant supply device according to claim 10, wherein the coupling device comprises a docking cylinder, which surrounds at least part of the cooling inlet.
 13. The grinding tool for use on a machine tool with tool-carrying work spindle, comprising a shaft, a grinding body provided on the shaft and a coolant supply device arranged on the shaft according to claim
 1. 14. The grinding tool according to claim 13, wherein the shaft has a tool connection for connecting the grinding tool to the work spindle of the machine tool and wherein the coolant supply device can be secured to the tool connection of the grinding tool.
 15. The grinding tool according to claim 12, wherein the coolant supply device is floatingly mounted on the grinding tool.
 16. The grinding tool according to claim 15, wherein a contour part is provided on the coolant supply device for the floating support of the coolant supply device, said contour part engaging in a second groove of the shaft of the grinding tool for supporting the grinding tool in an axial direction, and engaging in the first groove for supporting the slides in a radial direction.
 17. The grinding tool according to claim 12, wherein the clamping device secures in a securing position the coolant supply device to the shaft of the grinding tool in a radial direction and allows a rotation of the shaft about a longitudinal axis relative to the coolant supply device in a release position.
 18. The grinding tool according to claim 17, wherein the docking element is actuated for switching between the release position and the securing position.
 19. The grinding tool according to claim 12, wherein the slide of the coolant supply device is guided in the first groove, and wherein in the securing position the slide engages in the first groove of the grinding tool and in the release position the slide leaves the first groove so as to render possible a radial relative movement of the grinding tool to the coolant supply device.
 20. The grinding tool according to claim 12, wherein the discharge opening of the line unit is arranged in the region of the grinding body in such a way that a cooling lubricant can be supplied from the discharge opening into a work area of the grinding tool for the purpose of lubrication and/or cooling, wherein the alignment and/or orientation of the discharge opening of the line unit is mechanically, electrically, pneumatically and/or hydraulically adjustable and/or the line unit is releasably mounted.
 21. The grinding tool according to claim 12, wherein the docking element is movable along the movement axis which is parallel to the longitudinal axis of the shaft.
 22. The machine tool having a tool-carrying work spindle, which has a tool support and a connector ring, which is arranged in the region of the tool support, wherein the connector ring has at least one inner line system for coolant and a clamping device for clamping at least one engagement portion of a coolant supply device according to claim 1, and wherein a switching member is provided on the connector ring for switching the coolant flow from the inner line system of the connector ring to a docking device for coupling to the coolant supply device.
 23. The machine tool according to claim 22, wherein the machine tool comprises a tool changer and a tool magazine, and the tool changer is configured to exchange a tool which is clamped on the work spindle with a tool from the tool magazine, wherein a grinding tool for use on a machine tool with tool-carrying work spindle, comprising a shaft, a grinding body provided on the shaft and a coolant supply device arranged on the shaft, can be received together with the coolant supply device in the tool magazine and can be inserted at the work spindle by the tool changer.
 24. The machine tool according to claim 22, wherein while clamping the grinding tool on the work spindle the coolant flow is switched from the inner line system of the connector ring to the coolant supply device by contacting the coupling device of the coolant supply device with the switching member of the docking device of the connector ring.
 25. The machine tool according to claim 22, wherein the coolant supply device with the grinding tool is switched to the securing position when arranged in the tool magazine and is switched to the release position when arranged at the work spindle.
 26. The machine tool according to claim 22, wherein for docking the coolant supply device to the machine tool, the clamping device of the connector ring engages in the at least one engagement portion and the coolant supply device is pulled axially towards the connector ring and the grinding tool is received on the support of the work spindle of the machine tool, wherein a gap is adjusted between the coolant supply device and the grinding tool by the docking of the coolant supply device and the receiving of the grinding tool.
 27. The machine tool according to claim 22, wherein during docking the docking element is actuated.
 28. The machine tool according to claim 22, wherein the switching member has an inner cylinder and a switching sleeve guided on the inner cylinder, wherein for switching the coolant flow from the inner line system to the coolant supply device, the switching sleeve is moved relative to the switching cylinder by a docking cylinder of the coupling device to release switching holes of the inner cylinder and to redirect the coolant flow. 